Cheater!
by Potato-Post.Community
Summary: While Natsu's out on a job, Gray has a one night stand. What will happen when Natsu gets back?


**Heyo sprouts. So. Issa cheat fic. Sorry for making Gray a total asshole. (Maybe not total but y'know, cheating is pretty asshole-ish.) Gajeel and Natsu is my BrOTP btw. Well… all the dragon slayers together is my brOTP.**

 **Warnings: BoyxBoy, Bad writing**

 **Setting: Normal FT world (AU obviously because Gratsu isn't canon.)**

 **Disclaimer: I don't own Fairy Tail**

 **-FT-**

Natsu Dragneel firmly believed he could trust his boyfriend. He adored Gray with all his heart, and he _knew_ from the moment they met eyes that this man was his _forever_. His _mate_. Every time they touched, he felt a pleasing flutter in his stomach. Gray Fullbuster was _his_. _His, his,_ _ **his.**_ And _Mavis_ did Natsu _love_ him. He'd do _anything_ for the ice mage, and he was so _glad_ that Gray loved him back.

When he confessed to Gray, he could've sworn his heart _exploded_ out of pure happiness the moment the other said ' _I like you too,_ ' in one breathless remark. Natsu was expecting everything _other_ than the ice mage to say 'yes!'. He would've thought it'd be more disgust and fists, a tear between their already fragile friendship. So when those words slipped from the mage's lips, Natsu thought he was hallucinating. It took until the other smashed his lips against his, in an awkward and sloppy first kiss.

At first, they stuck to innocent touches and romantic outings. Natsu wanted to be sure Gray was fine with staying with him before _mating_ \- Mavis, thinking about it made his face go up in flames, (sometimes literally). After a few months the two finally made love and were officially _mates_. Natsu's already abused heart was about to _burst_ again. Gajeel was the first to congratulate them- figuring out before the rest because of Natsu and their scents.

Natsu, Gajeel and Wendy- sometimes also Sting and Rouge- were like siblings. But he still wasn't expecting Gajeel to pull Gray aside and give him the 'if you hurt Natsu, I hurt you' speech. Erza did the same thing, but _both_ of them got it. Gajeel and Natsu both knew that the pinkette would _never_ harm Gray, physically- well maybe physically, they still sparred and that was _pretty_ violent- or mentally. The ice mage however? There was nothing stopping him from doing either.

And that _scared_ Natsu.

Unlike Natsu, who was now mated for _life_ , Gray wasn't tied down. If he got tired of the pinkette? He could break up with the slayer without a second thought and Natsu would _break_. Gajeel sympathised with his fears. Gajeel wasn't sure Levy would actually ever _leave_ him, but it was still a constant fear in their life. Despite explaining about mating to Gray and Levy, they probably didn't understand said fear. (Although Natsu was certain Levy did. The girl was smart.)

But even despite the fears and uncertainties, he could look anyone in the eye and say ' _I trust Gray with all my heart._ ' Gajeel could stand up and say the same thing about Levy- (they don't talk about how Gajeel's voice would be more steady and 100% certain. They don't talk about how Natsu's palms would be sweaty, or how much his voice would shake or how his eyes would flitter away from the other's.)

Then came the day those fears came true for Natsu Dragneel.

Then came the day all his fragile trust _broke_.

Then came the day it all fell apart.

 **-FT-**

Gajeel was having a meh day. It was completely, utterly _normal_. He sat across from Levy and Pantherlily in one of the booths, nursing a glass of beer. Levy had insisted it was too early for it, but Gajeel argued that it was after noon. Now the topic was on Natsu and Gray. Natsu and Happy were out on a quick job- Natsu had wanted to give Gray a small gift and needed a few extra jewels- and was due back that night. Gray hadn't been spotted in the guild since Natsu left.

It was somewhat odd, Gajeel supposed. But who was he to judge? (He was a judging asshole and everyone knew that, but Natsu said he was a _loveable_ judging asshole. Levy agreed and Gajeel decked the pinkette.)

Somewhere deep inside him, he knew something was going to happen. He couldn't pinpoint it. So he allowed himself to get lost in the discussion of his 'brother' and Gray. Soon Lucy plopped down upon hearing the topic and the girls began squealing about when the duo would get married. Gajeel slumped in his seat, desperate to escape the conversation.

Then the doors opened and Gray walked in, shirt missing and hands in his pants pockets. Gajeel turned to greet him, but then he was assaulted by a foreign smell and something _not_ so foreign. (Gajeel wished he didn't have a dragon's nose because he could do without being able to smell _sex_.)

The smell was a mix of lilacs and cheap perfume, sex and desire. The lilac scent and cheap perfume obviously belonged to an unnamed woman, which meant…

" _FROSTY BASTARD!_ " Gajeel thrust himself up from his seat, fury oozing from his body.

"Gajeel! What the hell?" Levy pushed herself up too, intent on stopping his rage. This wasn't the normal 'guild brawl' anger she'd seen him carry when fighting Natsu, this was the 'I'll kill you where you stand' kind. "Calm down!" She latched onto his arm, pulling against his determined strides. He shook her off gently.

" _WHAT THE HELL IS WRONG WITH YOU?!_ " he bellowed. Gray stood, half confused and half panicked.

"What are you talkin' about, metal head?" Gray stated, calm as always. Gajeel could tell it was a fake calm. And _dammit_ Gajeel was going to _tear_ this man apart. A drop of sweat fell down the ice mage's face.

"You really think I can't _smell her_ on you?!" At this, the ice mage froze.

"I don't know what you're talking about..?" he tried. The taller- and older- male strode over, ignoring both Levy and Lucy's- (and the whole _guild's_ )- confusion.

"That's not something you should state as a question," Gajeel growled, "I can't believe you would fucking do this! Salamander will be able to smell her on you from a mile away!" Gray paled.

"I-I'll take a shower or something! Natsu can't know!" Gray was definitely feeling the pressure now. Behind them, the guild was muttering their confusion over 'Smell her? What does he mean? Smell who?'.

"It's too fucking late for that, ice boy." Then came the first punch. Gray was knocked halfway across the guild, only to slam into Macao and Wakaba's table. The two men let out cries of displeasure as their own glasses of beer were spilled- (Macao's spilling onto him). Gray groaned and forced himself to his feet just as the door was kicked open again.

Happy flew in, swirling in the air with glee. "GRAY! WE'RE BACK!" The small cat barreled into the mage's chest, knocking him back again. Natsu entered the guild a second after, face-splitting grin ever present. "Me and Natsu had to battle this _big, ugly lava monster_ , and it took so _long_!" The cat blabbered.

"Heyo, Gra-" Natsu's grin faltered and his eyes turned cold in the span of _seconds_. Gajeel swore he could hear Natsu's heart _break_ and _shatter_ , and his protective-older-brother instincts kicked in a second after. As much as he wanted to leap after Gray and beat him into the ground, he had to stand by. "T-This has to be… a _mistake_ right…? You wouldn't… _ever_ cheat…?" The iron slayer could _see_ the gears in Gray's head turn.

"I would _never_ , it's not what you're thinking, I promise. I'd never-"

" _DON'T LIE TO HIM, YOU PIECE OF SHIT!_ " Gajeel took a step forward again, but Natsu's overly warm hand was placed on his arm. The older male took a second to glance into the fire slayer's pain filled eyes.

"Gray…? Who… who was it…?" Natsu's grip was becoming tighter, but Gajeel wasn't about to shove him off.

"Trisha," Gray admitted quietly, "you wouldn't know her…" The pinkette's eyes watered.

" _Why_? _Why_ Gray..? Am… Am I not enough?" _Mavis_ , did Natsu sound so fragile. Others in the guild were staying silent. Mira looked like she wanted to ask just _what_ the hell was going on, Lucy looked like she wanted to comfort Natsu and Erza looked like she was going to _murder_ someone.

"That's not it! That's not it, I promise!" Gray looked like he was regretting his whole life and Gajeel couldn't help but think that he wanted him to feel _worse_. "Natsu- I-..."

"What the hell is going on?" Leave it to Erza to ask the real questions. "Who's Trisha?"

"Gray..?" Natsu asked again, sounding so _small_. His small hand slipped down to grip Gajeel's, something he had the habit of doing when he was younger and upset. His eyes wavered, finally landing on Gray's dark one's.

"I… Trisha- Listen, Natsu, I'm so sorry! I didn't mean it! It was one time and it'll never happen again-"

" _I DON'T WANT TO HEAR IT! YOU CHEATED, GRAY! DO YOU KNOW WHAT THAT MEANS?!_ " Natsu shrieked. Natsu's grip was getting unbearable. He was _crushing_ Gajeel's hand. Natsu was crying, _freely crying in front of everyone._ That was _bad_.

"You… cheated? _Gray_ , how could you?!" Mira blurted. The rest of the guild followed in suit, yelling out similar things. Erza's rage was exploding, and all Gray could do was cower.

"It was a _mistake_ , I swear!"

" _Gray!_ That doesn't _matter_! You _betrayed_ me, Gray! This is exactly what I was _afraid_ of!" He was full on _sobbing_ now, and Gajeel heard _everyone's_ \- including _Gray's_ heart- shatter. Happy was crying too, retreating from Gray, back to Natsu. He plopped down in the pinkette's hair to see if he could calm Natsu down a bit.

"Natsu, _please_ , I said it was a _mistake_! You're overreacting!"

" _YOU DON'T GET TO TELL ME THAT!_ " Gajeel tugged on the smaller's hand.

"C'mon. We're leaving," he whispered. Natsu hesitantly nodded, allowing Gajeel to pull him away. "We can go see Wendy and Sting and Rouge…" The trio disappeared.

Gray took a step forward, intent on running after them, but Erza pulled him back. "Gray, what the _hell_?"

"Look, I was tipsy and it was late," he started, "she was afraid of going home alone so I took her home and one thing lead to another…" Erza stared in disbelief.

"That's no excuse, Gray. You should've been the bigger person! You're mature enough to say _no_ ," she cried, stabbing her finger into his chest, "you _cheated_ , Gray. I hope you realize that not only did you break his _heart_ , but you broke his _trust_."

"I'll fix it then!"

"Give him time, Gray," Mira mumbled. Gray numbly nodded. "You just have to pray he'll forgive and forget."

"Yeah."

 **-FT-**

Thankfully, when he got home that night, Natsu was there. He was on the bed, knees tucked up to his chest and chin resting on them. Happy was absent, and so was Gajeel. Gray wondered if the two knew Natsu was there. Gray silently strode in, crouching down before his boyfriend's- he didn't want to think _ex-boyfriend-_ form. He grasped the smaller teen's hand.

"Natsu…" The boy unburied his face, and Gray brought his free hand to his tearful cheeks. He wiped away a tear. He gave Natsu a small kiss, mumbling apology after apology into his mouth. Natsu pulled back for a second, looking deep into Gray's eyes.

"I love you, Gray… don't you know that…?"

"I know that, I love you too. I love you, I love you, I _love you_." Fresh tears welled up in Natsu's eyes and he let them fall, smashing his lips against Gray's with desperation. Gray allowed Natsu's arms to wrap around his neck, pulling the two as closer as humanly possible. Gray's own hands traveled under and up Natsu's shirt, exploring the skin as if this was their first time all over again. It was messy- they both knew it- and full of need and want. Natsu broke the kiss for air, groaning as Gray's lips attacked his neck. His cold hands went to the band of Natsu's pants, and the pinkette's breathing hitched.

"I- Stop!" Gray retracted his hand immediately. "I can't… I keep imagining you with some _girl and I can't!_ " He buried his face in his palms, trying to smother and hide his sobs.

"It's okay, it's okay…"

"It's _not_ , Gray!"

"It'll never happen again! I promise!"

"I _know_ you promise! But- I _can't_ , Gray! _All I see is some random girl and you!_ " he wailed.

"Then we'll start over. We'll go slow. We don't have to-"

"I think we need to take a break, Gray." Natsu looked up and his eyes bored into Gray's and Gray wanted to _scream_.

"NO! Please, no! I can do better! I'll be better and I'll make it up to you… I _can't_ lose you because of some stupid mistake I made."

"Can… can we start over then…? I don't want to lose you either…"

"Of course. Of course. I promise I'll never ever do that again. Just you. Only ever you." Gray kissed Natsu deeply, letting his tongue explore the younger's mouth when he opened it. The pinkette nodded, sinking into the kiss.

"I think we're missing the rain.." he mumbled, "and the sappy music…"

"You're making enough rain for the both of us, Love. Light of my life, yee to my haw, yin to my yang." With every word, he peppered kissed to Natsu's already sun-kissed skin.

"And that was sappy enough for both of us too," Natsu wrapped his arms around Gray's torso, "I love you."

"I love you more…"

 **-FT-**

 **And that's a wrap. I could go for a wrap right now. Well, see you all next time! Don't forget to review, and all. BYE!**


End file.
